RE: Czech medical grounding?
Brent - 60601-1-1 has a requirement for use of an equipotential bonding terminal when the equipment is either Category AP Equipment or Category APG Equipment. These equipment types are related to flammable mixtures that are used for gaseous anesthetics and the requirement is intended to reduce the likelihood of ESD as a source of ignition. There is no exception stated for battery powered equipment and neither should there be, since many anesthetic gases are incredibly flammable and some are self oxidizing. If the product in question is Category AP Equipment or Category APG Equipment, the concern is legitimate. If not, it may relate more to the specific use environment in that particular hospital. For a reference, see the MSDS for cyclopropane http://www.matheson-trigas.com/msds/MAT06080.pdf One line from this MSDS is enough to give pause: "Electrostatic discharges may be generated by flow or agitation resulting in ignition or explosion." eek! Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services San Jose, CA peter.tar...@sanmina-sci.com > From: brent.dew...@us.datex-ohmeda.com > Sent: Friday, June 27, 2003 12:26 PM > > I got some weird "feedback" from one of our sales > people in the Czech > republic. One of the local folks said they were > concerned that a metal > cased piece of medical electrical equipment > didn't have a separate ground > for when it was used on internal batteries. I'm > an EMC guy so I was > wondering if any of the safety experts out there > could tell me if this > makes any sense from a regulatory standpoint. > > Thanks! > > Brent DeWitt > This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Czech medical grounding?
there is some consideration of this hazard in the EN-60601-1-1 Standard for Safety of Medical Electrical Systems Ged Dean From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: 29 June 2003 09:51 To: emc-p...@majordomo.ieee.org Subject: Re: Czech medical grounding? I read in !emc-pstc that Jon Griver wrote (in <3EFEAC1E.19777.64DE86@localhost>) about 'Czech medical grounding?' on Sun, 29 Jun 2003: >Theoretically, it could also be necessary for battery powered equipment >connected via a >communication line to equipment in another room. If the patient were to >accidently touch the metal >enclosure, a current loop could be closed, if the connection caused the >enclosure to be earthed at >a potential different from that of other equipment to which the patient may be >connected. This is more than 'theoretical'. The hazard presented by introducing a 'remote earth/ground' into an area is not documented in any standards or guides, AFAIK, and is thus not widely recognized. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. NCHT ** This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Czech medical grounding?
I read in !emc-pstc that Jon Griver wrote (in <3EFEAC1E.19777.64DE86@localhost>) about 'Czech medical grounding?' on Sun, 29 Jun 2003: >Theoretically, it could also be necessary for battery powered equipment >connected via a >communication line to equipment in another room. If the patient were to >accidently touch the metal >enclosure, a current loop could be closed, if the connection caused the >enclosure to be earthed at >a potential different from that of other equipment to which the patient may be >connected. This is more than 'theoretical'. The hazard presented by introducing a 'remote earth/ground' into an area is not documented in any standards or guides, AFAIK, and is thus not widely recognized. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Czech medical grounding?
Brent, On 27 Jun 2003 at 13:26, brent.dew...@us.datex-ohmeda.com wrote: > > I got some weird "feedback" from one of our sales people in the Czech > republic. One of the local folks said they were concerned that a metal > cased piece of medical electrical equipment didn't have a separate ground > for when it was used on internal batteries. I'm an EMC guy so I was > wondering if any of the safety experts out there could tell me if this > makes any sense from a regulatory standpoint. > This may be a reference to a Potential Equilization Terminal. This is not mandated by IEC 60601-1, but may be required by local authorities or hospital policy, particularly for use in operating theatres or intensive care units. The terminals on different pieces of equipment are connected together to ensure that all earth potentials are the same in order to prevent possible current loops through the patient. Theoretically, it could also be necessary for battery powered equipment connected via a communication line to equipment in another room. If the patient were to accidently touch the metal enclosure, a current loop could be closed, if the connection caused the enclosure to be earthed at a potential different from that of other equipment to which the patient may be connected. Regards, Jon Griver http://www.601help.com The Medical Device Developers Guide to IEC 60601-1 This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Czech medical grounding?
I read in !emc-pstc that brent.dew...@us.datex-ohmeda.com wrote (in ) about 'Czech medical grounding?' on Fri, 27 Jun 2003: >I got some weird "feedback" from one of our sales people in the Czech >republic. One of the local folks said they were concerned that a metal >cased piece of medical electrical equipment didn't have a separate ground >for when it was used on internal batteries. I'm an EMC guy so I was >wondering if any of the safety experts out there could tell me if this >makes any sense from a regulatory standpoint. I don't know about regulatory issues, but the equipment could accumulate a static charge, unless earthed (or bonded, anyway, to everything else in the area) and zap a patient in a sensitive spot. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Czech medical grounding?
I got some weird "feedback" from one of our sales people in the Czech republic. One of the local folks said they were concerned that a metal cased piece of medical electrical equipment didn't have a separate ground for when it was used on internal batteries. I'm an EMC guy so I was wondering if any of the safety experts out there could tell me if this makes any sense from a regulatory standpoint. Thanks! Brent DeWitt This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
